Jessica Chastain proved why she’s such a hot commodity in Hollywood this weekend during a performance of her Broadway show, “The Heiress.”

During a heated moment between her character, Catherine, and her father, played by David Strathairn, Chastain’s three-legged rescue dog, Chaplin, made a grand entrance… only he had no role in the play! The Saturday matinee crowd was aghast – and we were sitting in the second row to witness the action.

At first, the audience wondered if perhaps the pooch was part of the play – Chastain plays an heiress, after all, albeit one circa the 19th century – but as the Oscar nominee and Strathairn stared each other down (still totally in character), we quickly knew that wasn’t the case. The 35-year-old actress swiftly turned and walked Chaplin off the stage, never reaching down to pick him up or cracking so much as the slightest smile.

Like the pros they are, the two thespians allowed the audience a moment to laugh and get over the adorable disruption before continuing with their scene.

Thankfully, the “Zero Dark Thirty” heroine wasn’t all business when it came time for the curtain call. Chaplin got another moment in the spotlight in his owner’s arms as she laughed hysterically and took her bows.

“The Heiress” will continue its Broadway run through February 10, but don’t expect this to be the last you hear of it. Something tells us we’ll be talking about Chastain’s performance again come Tony Awards season.